Click Download now button and Choose your Linux Distribution ( I Chosen Ubuntu 10.04 32-bit. Note that if your Ubuntu version is higher than 10.04 you need to choose 10.04 package. Skype package is still old for Ubuntu )

Step 2:

Locate your downloaded file skype-ubuntu_4.0.0.7-1_i386.deb file ( My system it was in Downloads folder ). Right click and open with Ubuntu Software Center and Install.

skype install Ubuntu

Latest version Skype 4.0 successfully installed.

Skype 4.0 for Ubuntu/Linux

If you are using Ubuntu 12.04, Search Skype in HUD. Open skype and enjoy video and audio chatting free of cost !